/*
*  Copyright (c) 2001 Sun Microsystems, Inc.  All rights
*  reserved.
*
*  Redistribution and use in source and binary forms, with or without
*  modification, are permitted provided that the following conditions
*  are met:
*
*  1. Redistributions of source code must retain the above copyright
*  notice, this list of conditions and the following disclaimer.
*
*  2. Redistributions in binary form must reproduce the above copyright
*  notice, this list of conditions and the following discalimer in
*  the documentation and/or other materials provided with the
*  distribution.
*
*  3. The end-user documentation included with the redistribution,
*  if any, must include the following acknowledgment:
*  "This product includes software developed by the
*  Sun Microsystems, Inc. for Project JXTA."
*  Alternately, this acknowledgment may appear in the software itself,
*  if and wherever such third-party acknowledgments normally appear.
*
*  4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA"
*  must not be used to endorse or promote products derived from this
*  software without prior written permission. For written
*  permission, please contact Project JXTA at http://www.jxta.org.
*
*  5. Products derived from this software may not be called "JXTA",
*  nor may "JXTA" appear in their name, without prior written
*  permission of Sun.
*
*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
*  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
*  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
*  DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
*  ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
*  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
*  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
*  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
*  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
*  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
*  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
*  SUCH DAMAGE.
*  ====================================================================
*
*  This software consists of voluntary contributions made by many
*  individuals on behalf of Project JXTA.  For more
*  information on Project JXTA, please see
*  <http://www.jxta.org/>.
*
*  This license is based on the BSD license adopted by the Apache Foundation.
*
*  $Id: LegacyAnnounceFilter.java,v 1.6 2007/05/23 21:00:17 nano Exp $
*/

package net.jxta.myjxta.dialog.filter;

import net.jxta.logging.Logging;
import net.jxta.myjxta.dialog.DialogMessage;
import net.jxta.myjxta.dialog.DialogMessageWrapper;
import net.jxta.myjxta.dialog.util.Terms;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;

/**
 * @author james todd [gonzo at jxta dot org]
 * @version $Id: LegacyAnnounceFilter.java,v 1.6 2007/05/23 21:00:17 nano Exp $
 */

public final class LegacyAnnounceFilter
        extends AbstractDialogFilter {

    private final static String HELLO = "^(?i)\\*{3}\\s*has\\s*joined.*";
    private final static String GOODBYE = "^(?i)\\*{4}\\s*(.*)\\s*has\\s*left.*";
    private static final List<Pattern> patterns;

    private static final Logger LOG = Logger.getLogger(LegacyAnnounceFilter.class.getName());

    static {
        Terms terms = new Terms(new String[]{HELLO, GOODBYE});

        patterns = new ArrayList<Pattern>();

        for (Iterator<String> t = terms.getTerms(); t.hasNext();) {
            try {
                patterns.add(Pattern.compile(t.next()));
            }
            catch (PatternSyntaxException pse) {
                LOG.log(Level.FINE, "Caught unexpected Exception", pse);
            }
        }
    }

    /**
     * Invalidates messages that announce the arrival and departure of peers.  These messages come from the
     * InstantP2P (Legacy predicessor to MyJxta2) application.
     *
     * @param msg the newly received DialogMessage object
     * @return the newly modified DialogMessage object.
     */
    public DialogMessage filter(DialogMessage msg) {
        if (!processMessage((DialogMessageWrapper) msg)) {
            return msg;
        }

        String s = msg != null ? msg.getHtmlMessage() : null;
        boolean isLegacy = s == null;

        for (Iterator p = patterns.iterator(); p.hasNext() && !isLegacy;) {
            isLegacy = isLegacy || ((Pattern) p.next()).matcher(s).find();
        }

        if (isLegacy) {
            if (Logging.SHOW_FINE && LOG.isLoggable(Level.FINE)) {
                LOG.fine("Filtering out message " +
                        System.getProperty("line.separator") + msg);
            }
            ((DialogMessageWrapper) msg).setValid(false);
        }


        return msg;
    }
}
